Early Thursday morning, reports of gunshots filtered in to the security police — or SP — from concerned citizens near L. Mendel Rivers Elementary School on Altus Air Force Base.

Some have witnessed a man carrying a rifle and others have heard gunshots.

Within minutes, the SPs are on the scene, moving methodically through the hallways of the school and checking and clearing each classroom before moving on to the next location.

A duress tone echoes for about a minute, warning those in the vicinity of the school and other areas of the base of an active shooter.

Teachers and administrators alike are barricading themselves inside their offices and classrooms, staying as far away as possible from any door or window.

Some are tucked into the crawl space beneath their desks while others have secured improvised weapons to defend themselves and their co-workers if necessary.

In other areas, there are casualties.

Wounded are scattered throughout the hallways and classrooms, unable to escape the bullets of the gunman before being cut down.

The airmen know what to do in these types of situations, they have had years of training for scenarios just like this and luckily for the residents and workers on Altus AFB, this is another such exercise.

“This is an active shooter-based exercise and is used to test the response of our patrols — how they would react in a real-world situation, and how we would work with off-base agencies,” said Senior Airman Brandon Csady. “Usually it is a quarterly exercise. Flight level will do it about monthly, it just depends on what the flight chief wants to run that day.”

The exercises can last from one to two hours to complete a full exercise and is usually dependent upon the patrol’s response time and the number of agencies involved in the exercise.

If the SPs focus only on their first phase, it will be their response time of getting inside the building and getting to the shooter or shooters.

Once they have located the shooter, they must then focus on securing the shooter and the scene before completing their initial sweeps, their secondary sweeps and their exterior sweeps.

Once that is completed, they turn their focus to getting the victims out of the facility for treatment and corralling everybody to take accountability for each individual before the operation is turned over to a different on-scene commander who will go through the medical portion of the exercise.

But there is more to it than just sweeping a location. Often times, a different scenario develops and they are forced to assess the situation and formulate a different game plan.

“When we go in anywhere and we hear shots being actively fired, it is called going direct-to-threat,” Csady said. “So as we’re passing open rooms, we’re going to peek in as we’re going by but we’re not going to stop to fully clear that room out because we know there is a shooter somewhere else in that building. We’re going to go directly to where we hear that gunfire and we’ll take him out.”

“From there, we’ll secure the weapon and secure him and search him for any other weapons that he has on his body and if it is one shooter, we’ll have one person stay with the body and he’ll initiate a crime scene,” he said. “While he is doing that, all additional patrols will start their initial sweep, where they’ll sweep the facility to make sure there is not another shooter somewhere or any other devices. Then they will start their secondary sweep which is more in-depth. They’re going to open up cabinets and look for any devices that might be a bomb.”

If the situation is not direct-to-threat — shots are not actively being fired — the patrols will move from room-to-room, clearing each room as they go along.

They will search for people and ask the necessary questions to get as much information about the shooter as they can. From there, they will continue searching room-to-room until they find the shooter or shots are actively being fired, at which point they will continue as direct-to-threat.

One does not need to be a first responder to help in any situation. Csady has advice for anybody who finds himself or herself in this situation.

“What I always teach people who are not first responders is three main things — fight, escape or barricade,” Csady said. “Each one is dictated by the situation or where you are located in the building when the shooting starts. If a shooter walks into a room and begins shooting and you find yourself within 15 feet and you choose to fight them, you have a better chance of surviving if you can get ahold of that weapon. Escape is a better option, if you have the ability to escape, get out of the facility. The final one is barricade. If you can’t fight them and can’t escape and you’re inside an office, lock the door and turn off the lights and barricade the door with objects. You’re also going to want to grab an improvised weapon, whether it be a broom, a mop, or a fire extinguisher.”

“When first responders get on scene, the best thing anyone can do is listen to what the first responder is telling them to do,” he said. “If they’re yelling hands, hands, hands, get on the ground, just get on the ground. At that point the first responder doesn’t know them and are trying to assess the person and make sure they are not a threat to them or their partner. Once they ask their questions and make sure the person is not a threat, they are going to direct them where to go.”

“With the world we live in today, active shooters are a very real thing,” he said. “Anybody can turn into an active shooter. They are unpredictable. An active shooter can happen at any time and that is why we do this training so that we are always prepared for when or if this happens.”